Usually the engine on this car is faultless, but today, started up OK, but seemed very lumpy for around 5mins, idled OK, but under acceleration seemed like it was misfiring (if it was a petrol). After 5 mins, possible less, everything was fine, no loss of power etc, and no smoke. When i left work this evening, was the same, but only for about a min or so. no dash lights at all. Recently put in diesel injector cleaner that was recommended on here BG244, around a month or so ago.

Could this be glow plugs, or a blocked injector?? Anything I should do. Car serviced every 12.5K miles, and mainly does motorway runs.

Got an 07 with 41k on the clock and mine does the exact same thing but it has only just started which I find strange. I do drive lightly until the engine warms up so I'm not too concerned! I would put this down to being a characteristic of this engine when cold. Once the water temp starts to rise the lumpyness disappears and the engine performance is top notch. I always fill up with BP fuel but I put a tank of Shell last week and it's still the same!

Well it started doing this again. After the first time, it went right after a couple of days. Last week did it again for 2 days, stopped after I gave it 2 goes with the glow plugs. Today its started doing it again. Feels like a misfire, until I get to the end of the close I live in. When revved, it struggles, but once this has gone away at the end of the road, engine is fine, with normal MPG, and pulling. I hope its nothing serious, recently did an interim service (oil/filter and air filter), fuel filter was done 6 months ago. No smoke or anything. car has done 80000 miles, all predominantly motorway.

The engine is just cold. We also have a 59 plate 1.6 TDCi with 36k miles and it's the same. If it was a fuel problem you'd feel a hesitation when you step on the throttle peddle. The glow plugs are just for starting and wouldn't cause this. Do you just start up and then set off on your journey?

Yeah, I set off as soon as its started. Its odd this has only just started, last winter with the dreadful snow it was fine. This is why I thought a faulty glow plug, would not heat up the cylinder as well as it should, so the diesel would not burn properly.....

Chris, I know what you mean about it being odd, you definitely notice the lumpiness. We got some cold weather coming up so we'll see what happens? Try idling for 3 mins before you set off, helps prolong the turbo too! I know last winter with the temps often in -7deg C if I pre-heated it twice is started one time with minimal cranking.

What fuel economy are you getting? I'm getting 45-48mpg depending on route. The on board read out for me is pretty spot on with actual distance traveled against fuel used.

Thanks for the info Tom, it's nice to be aware of these things. I had a look in the engine bay last week with a mirror and torch checking for leaks etc and all looks well.

isx600..... Thanks, its been ok the past couple of days, but even though raining and windy, amvient temp around 14degrees. Will have to wait and see I think.... Usually get around 59-63mpg, but all the car usually does is motorway driving.

Dont think its anything serious, as apart from this engine runs and pulls absolutely fine and MPG is not going through the floor.....

My car had an oil and filter change and the lumpiness has gone! Oil used was Shell Helix. Put 2k miles on it since the service and still as smooth as the day the oil got changed.

Adam

Its gone on mine too... After my last post it just went away, and never returned. Brother in law, who's a mechanic, did an interim service on it (Oil/Filter and cleaned the pipercross filter which was filthy, although only done a few thousand miles on it) The issue has never reappeared, and now the weather is very cold. Starts first turn of the key, and is faultless..... Ive just put it down to one of those things To be honest I am not sure what the timescales were between the service and it going away....

PS brother in law never thought it was anything to be concerned about :-)

Found this old thread which best describes what has started on my 07 tdci. I have noticed it once or twice before, but very subtle, and then on the weekend it happened much more strongly that my passengers also noticed. Only happened when the engine was cold within 3 or 4 minutes of starting up, and only at low revs like when coasting into a roundabout and then pulling away. It starts fine first time and idle revs are stable, and can't feel it if I pull through to higher revs. It happened at the start of a 500 mile trip back from holidays so I was a bit worried but then it cleared when the engine warmed up and drove fine. BTW the car is coming up to 100k miles and all foil and filter services are up to date.

Have you checked your coolant level from cold and just have a look to see if you have any leaks reason I say this is cos mine started doing this and the thermostat housing had sprung a leak I had known about it for a while but when the water got to lw I had the symptons you describe since I,ve changed it and topped everything back up I have not had this problem .might just be coincidence or something to do with cold start thermostat like a choke on a petrol I don't know but it's cured it

Thanks for the reply. I have noticed before that the coolant level is quite low so will go out and check to see if it has dropped some more. I would have thought low coolant would lead to problems once the engine has warmed up by overheating, especially as I did a 500 mile non stop trip in warm weather on Sunday. But if thats the problem I'm more thn happy that is all that is needed to fix it. Will report back when I have had a look.